1. Field of the Invention
The present invention relates to an ultrasonic imaging system and, more particularly, to an ultrasonic imaging system having a real-time arbitrary mmode.
2. Description of the Related Art
Ultrasonic imaging systems are widely used to produce an image of the inside of a person""s body.
FIG. 1 is a diagram illustrating the general concept of an ultrasonic imaging system. Referring now to FIG. 1, an ultrasonic imaging system 18 typically includes electronics 20 and a transducer 22. Electronics 20 produces control signals for a transducer 22. In accordance with the control signals, transducer 22 transmits ultrasonic energy 24 into tissue 26, such as that, for example, in a human body. Ultrasonic energy 24 causes tissue 26 to generate a signal 28 which is received by transducer 22. Electronics 20 then forms an image in accordance with the received signal 28.
There are many xe2x80x9cmodesxe2x80x9d of operation for an ultrasonic imaging system.
FIG. 2 is a diagram illustrating scan lines in a conventional bmode, often referred to as brightness mode, of an ultrasonic imaging system. Referring now to FIG. 2, the ultrasonic imaging system produces a plurality of scan lines 30a through 30n. Generally, each scan line represents a narrow ultrasonic transmission and receipt of the generated signal in the direction of the scan line. Generally, the ultrasonic imaging system produces scan lines 30a-30n in sequential order to sweep across the intended target through a sufficient angle xcex8 which might be, for example, 90xc2x0. Of course, FIG. 2 is only an example to illustrate bmode, and is not drawn to scale. Moreover, the number of scan lines and the specific angle xcex8 are only intended as examples, and bmode is not limited by these examples.
Bmode provides only limited information. Therefore, an ultrasonic imaging system might also include a conventional mmode.
FIG. 3 is a diagram illustrating a conventional mmode display. Referring now to FIG. 3, a plurality of mmode scan lines 34a through 34x are displayed. Each mmode scan line 34a through 34x indicates depth into the target tissue. Although not shown in FIG. 3, each mmode scan line 34a through 34x uses a grey scale to indicate intensity in the depth direction.
Each mmode scan line 34a through 34x represents a scan of the same line through the target tissue, but taken at a different time. Therefore, the plurality of mmode scan lines 34a through 34x, taken together, provide information relating to depth into the target tissue over time for the same line. The above-described mmode may hereafter be referred to as xe2x80x9cregularxe2x80x9d mmode.
Bmode scan lines and regular mmode scan lines are displayed in real-time. Often, bmode and regular mmode are shown together on the same display, as these different modes, taken together, provide a significant amount of useful information in real-time.
FIG. 4 is a diagram illustrating a bmode display showing various organs within the human body. Referring now to FIG. 4, a bmode display 40, which is a two-dimensional ultrasonic image, might show, for example, a septum 42 inside a human body. Straight line 44 represents a specific mmode scan line which might be scanned over time as regular mmode. Then, a plurality of mmode scan lines taken over time along straight line 44 might be displayed as a regular mmode display such as that, for example, in FIG. 3.
As can be seen from FIG. 4, a regular mmode scan is taken along a straight line, such as straight line 44. However, for many reasons, it is desirable to provide an mmode scan along a user-defined curve, which might not be a straight line. For example, a user might desire to provide an mmode scan along curve 46 which more closely follows curves of tissue inside the human body.
Therefore, a conventional ultrasonic imaging system might include xe2x80x9carbitraryxe2x80x9d mmode (often referred to as anatomical mmode). Arbitrary mmode is similar to regular mmode in that arbitrary mmode is a time versus depth display with gray scale used to show the intensity of the received signal. However, in arbitrary mmode, the data is acquired along a user defined curve within a two-dimensional ultrasonic image. For example, arbitrary mmode can provide data along curve 46 in FIG. 4.
However, while regular mmode is a real-time display, arbitrary mmode is not performed in real-time. Instead, arbitrary mmode is performed as a post-processing operation on stored two-dimensional images. This is a significant disadvantage of arbitrary mmode, as it would be much more preferable to perform arbitrary mmode in real-time.
Moreover, since arbitrary mmode is performed as a post-processing operation on stored two-dimensional images, the user is undesirably restricted to the two-dimensional frame rate for the time interval between arbitrary mmode lines.
Accordingly, the present invention provides an ultrasonic imaging system having a real-time arbitrary mmode.
Moreover, the present invention provides an apparatus including (a) a scan converter scan converting portions of slices in real-time of a two-dimensional ultrasonic image which form an arbitrary user-defined curve within the two-dimensional ultrasonic image; (b) an image buffer, the scan converter drawing the scan converted portions into the image buffer; and (c) a display displaying the curve as a time versus depth image from the scan converted portions drawn into the image buffer.
Further, the present invention provides a method including (a) producing a two-dimensional ultrasonic image; and (b) producing a real-time mmode image of ultrasonic data acquired along an arbitrary user-defined curve within the two-dimensional ultrasonic image.
The present invention also provides a method including (a) scan converting portions of slices in real-time of a two-dimensional ultrasonic image which form an arbitrary user-defined curve within the two-dimensional ultrasonic image; and (b) displaying the curve as a time versus depth image from the scan converted portions.
Additional advantages, features and embodiments of the invention will be set forth in part in the description which follows, and, in part, will be obvious from the description, or may be learned by practice of the invention.